from __future__ import annotations

from dataclasses import dataclass, field
from typing import Any, Callable

from .models import PipelineState, ProviderError


PIPELINE_STARTED = "pipeline_started"
WAKE_LISTENING = "wake_listening"
WAKE_DETECTED = "wake_detected"
ACK_STARTED = "ack_started"
QUESTION_PROMPT = "question_prompt"
CAPTURE_STARTED = "capture_started"
SPEECH_STARTED = "speech_started"
SPEECH_ENDED = "speech_ended"
STT_STARTED = "stt_started"
TRANSCRIPT_PARTIAL = "transcript_partial"
TRANSCRIPT_FINAL = "transcript_final"
LLM_STARTED = "llm_started"
TTS_STARTED = "tts_started"
PLAYBACK_FINISHED = "playback_finished"
STANDBY_RESUMED = "standby_resumed"
STAGE_ERROR = "stage_error"
RECOVERING = "recovering"


@dataclass(frozen=True, slots=True)
class PipelineEvent:
    type: str
    turn_id: int | None = None
    state: PipelineState | None = None
    message: str = ""
    payload: dict[str, Any] = field(default_factory=dict)


class PipelineEventBus:
    def __init__(self) -> None:
        self.events: list[PipelineEvent] = []
        self._listeners: list[Callable[[PipelineEvent], None]] = []

    def subscribe(self, listener: Callable[[PipelineEvent], None]) -> None:
        self._listeners.append(listener)

    def emit(
        self,
        event_type: str,
        *,
        turn_id: int | None = None,
        state: PipelineState | None = None,
        message: str = "",
        payload: dict[str, Any] | None = None,
    ) -> PipelineEvent:
        event = PipelineEvent(event_type, turn_id=turn_id, state=state, message=message, payload=payload or {})
        self.events.append(event)
        for listener in list(self._listeners):
            listener(event)
        return event


def dispatch_pipeline_event(reporter: Any, event: PipelineEvent) -> None:
    if event.type in {TRANSCRIPT_PARTIAL, TRANSCRIPT_FINAL}:
        reporter.transcript(
            str(event.payload.get("text", event.message)),
            final=event.type == TRANSCRIPT_FINAL,
            turn_id=event.turn_id,
        )
        return
    if event.type == STAGE_ERROR:
        error = event.payload.get("error")
        if isinstance(error, ProviderError):
            reporter.error(error.stage, error.code.value, error.message, turn_id=event.turn_id)
            return
        reporter.error(
            str(event.payload.get("stage", "pipeline")),
            str(event.payload.get("code", "STAGE_ERROR")),
            event.message,
            turn_id=event.turn_id,
        )
        return
    if event.message:
        reporter.status((event.state.value if event.state else event.type), event.message, turn_id=event.turn_id)